Empathy-driven fear responses in mice are governed exclusively by the right-side pathway of the LC-ACC circuit—a neural connection between the locus coeruleus (LC) and the anterior cingulate cortex (ACC). (Image created by AI/ChatGPT)
SEOUL, April 1 (Korea Bizwire) — A team of South Korean neuroscientists has uncovered a brain circuit that selectively activates in the right hemisphere when individuals experience empathy, providing fresh insight into how the brain processes others’ pain—and potentially offering a new framework for treating empathy-related disorders.
The study, conducted by researchers from the Cognitive and Sociality Research Group at the Institute for Basic Science (IBS) and led by Dr. Shin Hee-sup, found that empathy-driven fear responses in mice are governed exclusively by the right-side pathway of the LC-ACC circuit—a neural connection between the locus coeruleus (LC) and the anterior cingulate cortex (ACC).
While the LC-ACC circuit is symmetrically connected across both hemispheres of the brain, the researchers discovered that only the right-side pathway is activated when mice observe another mouse in distress, suggesting a functional lateralization of empathy in the brain.
The LC, a brainstem nucleus responsible for arousal and alertness, and the ACC, located in the frontal lobe and associated with pain processing, were studied using advanced techniques such as optogenetics (which uses light to control neurons) and calcium imaging (to monitor neuron activity).
In one experiment, mice exhibited “freezing” behavior—a fear response—after observing another mouse receiving electric shocks. When the right-side LC-ACC pathway was inhibited, the empathetic freezing response sharply diminished. In contrast, suppressing the left-side pathway had no effect, confirming the right hemisphere’s dominant role in empathetic fear.
Only the right-side pathway is activated when mice observe another mouse in distress, suggesting a functional lateralization of empathy in the brain. (Image courtesy of Pixabay/CCL)
Interestingly, when mice were subjected to electric shocks themselves (direct fear), suppressing either side of the LC-ACC pathway did not reduce their fear response, indicating that the circuit is specifically tuned to empathetic, not personal, fear.
The study also identified higher-order regulators of this emotional circuitry. The bed nucleus of the stria terminalis (BNST) was found to modulate empathetic responses by activating the LC-ACC pathway, while the central amygdala responded primarily to direct fear stimuli.
“This study reveals for the first time that empathy is functionally lateralized to the right hemisphere of the brain,” said Dr. Shin. “These findings could provide a neurological basis for treating disorders such as antisocial personality disorder or autism spectrum disorder, where empathy processing is impaired.”
The full study was published online on March 10 in the journal Nature Communications.
Lina Jang (linajang@koreabizwire.com)
